1. Field of the Invention
It is well-established that snoring and sleep apnea are sleeping problems that effect the quality of life of many people. Snoring is generally caused by the vibration of soft tissue and tongue against the back of the throat, which can be caused by restricted airflow through the pharyngeal passageway. Both the person snoring and other persons nearby can be affected by the resulting noise.
The relaxation of muscles during sleep can allow the structures and tissues of the nose and mouth to fall backwards against the back wall of the throat. While partial airflow restriction results in snoring, more complete obstruction can result in sleep apnea, also known as obstructive sleep apnea (OSA). OSA can result in the stoppage of breathing for short periods, which causes the sufferer to gasp for air, causing a change in the contraction of muscles and resulting significant disruptions in sleep patterns. With a lower quality of sleep, the sufferer may experience fatigue-induced problems such daytime sleepiness, depression, and other related problems. More severe complications such as heart attack or stroke can also be associated with decreased airflow and reduced blood-oxygen saturation levels.
Therefore, opening the pharyngeal passageway for increased airflow while sleeping can eliminate or significantly reduce snoring and OSA, and the resulting benefits are apparent.
Numerous methods for preventing snoring and/or OSA currently exist. One method is the advancement of the mandibular structure relative to the maxillary structure. It has been established since the 19th century that advancing the mandible results in increased airflow through the pharyngeal passageway. Thus advancement of the mandible while sleeping can reduce or eliminate snoring and/or OSA.
2. Description of Related Art
Numerous devices exist to advance the position of the mandible, and therefore prevent snoring and OSA. Such devices are in the form of a oral appliance worn by the user while sleeping. However, all such devices previously known face certain limitations. One common limitation is that custom molding is often required to shape the device to a user's teeth or mouth. This requires the expertise of a medical professional such as a dentist, and is therefore expensive and time-consuming. Additionally, many devices restrict the physiological movement of the user from freely opening and closing their jaw when the device is placed in the mouth. This is uncomfortable and unnatural for many users. The upper and lower trays of many devices force the jaw in a fixed, nearly closed, or closed position. A device which, by design, is not allowed to close completely would aid in the flow of air through the mouth.
U.S. Pat. No. 6,129,084 (Bergersen) describes an intra-oral device for advancing the user's mandible. The device is comprised of two u-shaped plates joined to form a hinge. The lower plate includes a channel. This lower plate channel has an inner wall (lingual wall), which faces the user's tongue, and an outer wall (labial-buccal wall), which faces the user's cheek and lips. Thus the user's mandibular teeth are cradled in the lower channel. The upper plate contains an outer wall (labial-buccal wall), but does not include an inner wall (lingual wall). The lack of an inner wall is to position the user's tongue in contact with the lingual side of the user's maxillary teeth, meaning the inside of the user's upper teeth. The preferred embodiment of this device is molded from pliable material in one piece and uses a simple hinge mechanism. The hinge is comprised simply of a thinning of the cross-section of the molded material, which allows the device to bend. It is described that the hinge may be sufficiently rigid to maintain a substantial gap in an open position, even when the user applies considerable force.
This '084 device, however, faces numerous limitations. The simple hinge mechanism is subject to wear as the pliable material is bent over many cycles of the user's mouth opening and closing. The mandibular advancement the device provides is created solely by the position of the hinge. Fatigue of the, material, compounded by a lack of mechanical reinforcement, may allow the simple living hinge to become sloppy and loose, rendering the device unable to properly advance the mandible. In addition, there's no mechanical element to prevent the device from completely closing, causing upper surface 24 and lower surface 14 to become co-planar.
U.S. Pat. No. 6,055,986 (Meade) describes a mandibular advancement mouthpiece that includes a hard shell that holds a soft, moldable material. The soft material rests against the teeth. The device is made in two major halves, an upper member and a lower member. One embodiment contains reciprocal surfaces 222 and 224 which fit together to fix the relative forward and backward positions of the upper and lower members to each other. However, with this device the upper and lower members are not connected or hinged to one another. Rather, this device relies on the material being molded to the user's individual teeth and the resulting contact adhesion in order to stay in place in the mouth.
U.S. Pat. No. 6,170,485 (Orrico) also describes system with two halves. It also uses moldable inner trays to interface with the teeth. It further describes tongues 30 and 32 which extend out of person's mouth. One tongue includes a plurality of holes 34, while the other tongue includes a projection 36. The projection aligns with one of the holes to create mandibular advancement, with different holes creating different amounts of advancement. However, with this device the upper and lower member's are not connected or hinged to one another. Rather, this device relies on the material being molded to the user's individual teeth and the resulting contact adhesion in order to stay in place in the mouth.
U.S. Pat. No. 5,829,441 (Kidd) also describes system with two halves. It also uses moldable material to interface with the teeth. Means are included for adjustably advancing the user's mandible. However, this device requires the user to sleep with their jaw in a fixed, clenched position. Many people find sleeping with their jaw in a fixed position to be very uncomfortable, potentially even inhibiting sleep.
U.S. Pat. No. 6,516,805 (Thorton), as well as its related parent application, also describes a system with two halves. It also uses moldable material to interface with the teeth. A post 16 extends from the upper arch 12 and contacts the lower arch 14 to extend the user's mandible. However, this two-half design requires the post to be positioned at the front of the upper arch. Thus the post may disengage from the lower arch when the mouth is opened, causing the mandible to no longer be in an advanced position. In addition, there's no mechanical element to prevent the device from completely closing, causing upper arch and lower arch become co-planar.
U.S. Pat. No. 5,499,633 (Fenton) describes a system with two halves. It includes apertures 40 and projections 36. The projections are received into the apertures, therefore creating mandibular extension. However, with this device the upper and lower members are not securely connected or hinged to one another. The projections are made from the soft, moldable material of the rest of the device, and as such, may be difficult to engage in the apertures. In addition, the soft material of the projections may allow movement between the upper and lower members, thus not consistently advancing the mandible. In addition, the two members of the device may easily disengage from the teeth through the natural movement of the jaw. The device also requires boiling and molding.
U.S. Pat. No. 1,146,264 (Kelly) describes a dental splint. As best understood, this device use two separate trays to hold the jaw in position, with the trays apparently cemented to the user's teeth. This is used to create a static position if the bones of the jaw are fractured and must heal. It recites pillars 18, which hold the trays apart so that food may be inserted into the user's mouth.
U.S. Pat. No. 4,376,628 (Aardse) describes a tooth-treating mechanism in two halves It includes parallel ridges 9 and 10. The ridges serve to center one device half over the other device half. The orientation of the ridges does not create mandibular advancement, as they are in a direction perpendicular to that required for mandibular advancement.
CA 2,177,284 (Voss) describes a one-piece mandibular advancement device. This device is molded from pliable material in one piece and uses a simple hinge mechanism. The hinges 4 and 4′ are comprised of a thinned cross-section of the molded material, in conjunction with half-cylinder 40 and notch 41. This assembly allows the device to bend. This device, however, faces numerous limitations. The simple hinge mechanism is subject to wear as the pliable material is bent over many cycles of the user's mouth opening and closing. The mandibular advancement the device provides is created solely by the position of the hinge, and faces similar limitations to the device described in '084 (Bergersen) In addition, there's no mechanical element to prevent the device from completely closing, causing upper surface 24 and lower surface 14 to become co-planar and therefore restricting airflow through the mouth.
Other mandibular devices are disclosed in patents and in the marketplace as well. However, all face similar limitations as the above described inventions. In summary, many of the above devices require fitting, molding, or adjustment by a dental professional and fabrication laboratory. This process is costly and time-consuming, and prevents by non-skilled persons using the device straight-out-of-the-package. Still other systems use a simple hinge that quickly wears and may no longer properly advance the mandible. Many of these devices also restrict the user from opening his/her mouth, which many users find undesirable.